China patent No. CN101593686A disclosed an integration flow for fabricating the metal gate. It select amorphous carbon as the sacrificial gate material and form the substrate structure which is needed by the Gate-last craft. It comprise the specific process flow of forming gate dielectric layer on substrate; forming patterning amorphous carbon layer on said gate dielectric layer; spacer around said patterning amorphous carbon layer; forming inter-layer dielectric which cover said spacer around patterning amorphous carbon layer; planarizing said inter-layer dielectric and exposing said patterning amorphous carbon layer; using oxygen ashing process to remove said patterning amorphous carbon layer; forming trench in said inter-layer dielectric; forming metal layer which fill said trench and cover said inter-layer dielectric.
The process provided by the patent mentioned above is very simple, so detailing is needed to quite a few process of the method. For example, the laminated structure before the gate is shaped up; the process before the sacrificial gate is shaped up; the process after the sacrificial gate is shaped up; the formation process of conventional spacer structure; the preparatory work of substrate for ion implant process; treatment process of Stress Proximity Technology (SPT); treatment process of Contact etch stop layer; treatment process before the Chemical Mechanical Polishing, etc.